Adjustable contact jaw spacing for circuit breaker plug-in base

Abstract

A method of adjusting spacing between first and second jaw structures of a plug-in base for receiving a circuit breaker is provided. The method includes providing a plug-in base 10 having first and second jaw structures constructed and arranged to receive stabs of a circuit breaker. The first jaw structure 14 is disposed in a first housing 18 and the second jaw structure 16 is disposed in a second housing 20. Each of the first and second housings has an upper surface 22 and an opposing lower surface 24. A first spacer 26 is placed between the first jaw structure 14 and the upper or lower surface of the first housing 18 and a second spacer 28 is placed between the second jaw structure 16 and the upper or lower surface of the second housing 20 to define a certain spacing between the first and second jaw structures.

What is claimed is:  
     
       1. A method of adjusting spacing between first and second jaw structures of a plug-in base for receiving a circuit breaker, the method including: 
       providing a plug-in base having first and second jaw structures constructed and arranged to receive stabs of a circuit breaker, said first jaw structure being disposed in a first housing and said second jaw structure being disposed in a second housing, each of said first and second housings having an upper surface and an opposing lower surface, said first and second housings being spaced a prescribed distance apart,  
       placing a first spacer between said first jaw structure and one of said upper and lower surfaces of said first housing; and  
       placing a second spacer between said second jaw structure and one of said upper and lower surfaces of said second housing,  
       wherein each of said spacers is placed by removing a mounting fastener which mounts an associated bus with respect to a respective jaw structure, removing each bus from the plug-in base, placing each spacer against one of the upper and lower surfaces of the associated housing, reconnecting each bus to the plug in base and replacing each mounting fastener,  
       whereby placement of said first and second spacers defines a certain adjustable spacing between said first and second jaw structures without the need to adjust the prescribed distance between the first and second housings.  
     
     
       2. The method according to  claim 1 , wherein said first spacer is placed between said first jaw structure and said upper surface of said first housing with said first jaw structure contacting said lower surface of said first housing, and said second spacer is placed between said second jaw structure and said lower surface of said second housing with said second jaw structure contacting said upper surface of said second housing. 
     
     
       3. The method according to  claim 1 , wherein said first spacer is placed between said first jaw structure and said lower surface of said first housing with said first jaw structure contacting said upper surface of said first housing, and said second spacer is placed between said second jaw structure and said upper surface of said second housing with said second jaw structure contacting said lower surface of said second housing. 
     
     
       4. The method according to  claim 1 , wherein said first and second spacers are made of electrically insulating material. 
     
     
       5. The method according to  claim 1 , wherein each said bus has a slotted hole for receiving the mounting fastener, each said bus including a protrusion, said plug-in base including a pair of receiving slots, the step of reconnecting each bus including placing said end of each said bus into a said receiving slot so that said protrusion engages said plug-in base and placing the fastener into the slotted hole to mount each bus with respect to an associated jaw structure. 
     
     
       6. The method according to  claim 1 , wherein each said bus has a slotted hole for receiving the mounting fastener, said plug-in base including a pair of inner walls each defining a stop surface, the step of reconnecting each bus including ensuring that a surface of each said bus engages a stop surface and placing the fastener into the slotted hole to mount each bus with respect to an associated jaw structure. 
     
     
       7. A plug-in base for a receiving a circuit breaker, the plug-in base comprising: 
       a main body portion having first and second jaw structures constructed and arranged to receive stabs of a circuit breaker, said first jaw structure being disposed in a first housing and said second jaw structure being disposed in a second housing, each of said first and second housings having an upper surface and an opposing lower surface, said first and second housings being spaced a prescribed distance apart,  
       a first spacer between said first jaw structure and one of said upper and lower surfaces of said first housing;  
       a second spacer between said second jaw structure and one of said upper and lower surfaces of said second housing; and  
       a bus associated with each of said first and second jaw structures, each said bus being connected to an associated jaw structure by a fastener, each said bus being constructed and arranged with respect to an associated jaw structure such that removal of said fastener and of said associated bus permits access to a spacer within an associated housing,  
       whereby said spacers define a certain adjustable spacing between said first and second jaw structures without the need to adjust the prescribed distance between the first and second housings.  
     
     
       8. The plug-in base according to  claim 7 , wherein said first spacer is disposed between said first jaw structure and said upper surface of said first housing with said first jaw structure contacting said lower surface of said first housing and said second spacer is disposed between said second jaw structure and said lower surface of said second housing with said second jaw structure contacting said upper surface of said second housing. 
     
     
       9. The plug-in base according to  claim 7 , wherein said first spacer is disposed between said first jaw structure and said lower surface of said first housing with said first jaw structure contacting said upper surface of said first housing and said second spacer is disposed between said second jaw structure and said upper surface of said second housing with said second jaw structure contacting said lower surface of said second housing. 
     
     
       10. The plug-in base according to  claim 7 , wherein each said bus has a slotted hole for receiving said fastener, each said bus including a protrusion, said plug-in base including a pair of receiving slots, each bus being received in a said receiving slot so that said protrusion engages said plug-in base with said fastener disposed through the slotted hole to mount each bus with respect to an associated jaw structure. 
     
     
       11. The plug-in base according to  claim 7 , wherein each said bus has a slotted hole for receiving the mounting fastener, said plug-in base including a pair of inner walls each defining a stop surface, an end of each said bus engaging a stop surface with said fastener being disposed through the slotted hole to mount each bus with respect to an associated jaw structure. 
     
     
       12. The plug-in base according to  claim 7 , wherein said first and second spacers are made of electrically insulating material.